#include <bits/stdc++.h>

#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define in read<int>()
#define lin read<ll>()
#define rep(i, x, y) for(int i = (x); i <= (y); i++)
#define per(i, x, y) for(int i = (x); i >= (y); i--)

using namespace std;

using ll = long long;
using db = double;
using pii = pair < int, int >;
using vec = vector < int >;
using veg = vector < pii >;

template < typename T > T read() {
	T x = 0; bool f = 0; char ch = getchar();
	while(!isdigit(ch)) f |= ch == '-', ch = getchar();
	while(isdigit(ch)) x = x * 10 + (ch ^ 48), ch = getchar();
	return f ? -x : x;
}

template < typename T > void chkmax(T &x, const T &y) { x = x > y ? x : y; }
template < typename T > void chkmin(T &x, const T &y) { x = x < y ? x : y; }

const int N = 1e5 + 10;
const int K = 18;

int n, m, Q;
ll tot;

namespace ori {
	vec G[N];
	int dfn[N], R[N], dep[N], tim, ind[N], siz[N];
	void dfs(int x, int p) {
		siz[x] = 1; dep[x] = dep[p] + 1; ind[dfn[x] = R[x] = ++tim] = x;
		for(auto y : G[x]) if(y ^ p) dfs(y, x), R[x] = tim, siz[x] += siz[y];
	}
	void solve() {
		n = in, m = in, Q = in; rep(i, 2, n) { int u = in, v = in; G[u].eb(v); G[v].eb(u); }
		dfs(1, 0); 
	}
}

using namespace ori;

vec g[N];
int fa[N], id[N];

int lca(int x, int y) {
	if(dep[x] < dep[y]) swap(x, y);
	while(dep[x] > dep[y]) x = fa[x];
	while(x ^ y) x = fa[x], y = fa[y];
	return x;
}

ll dist(ll x, ll y) { return dep[x] + dep[y] - dep[lca(x, y)] * 2; }

void tdfs(int x, int p) {
	dep[x] = dep[p] + 1; fa[x] = p; for(auto y : g[x]) tdfs(y, x);
}

void copytree(int x, int anc) {
	vec pot;
	rep(i, dfn[x], R[x]) pot.eb(ind[i]);
	sort(pot.begin(), pot.end());
	for(auto t : pot) id[t] = ++tot;
	if(anc) g[anc].eb(id[x]);

	for(auto t : pot) {
		x = id[t]; for(auto y : G[t]) if(dfn[y] >= dfn[t] && dfn[y] <= R[t]) g[x].eb(id[y]);
	}
	tdfs(1, 0);
}

int main() {
#ifndef ONLINE_JUDGE
	freopen("1.in", "r", stdin); freopen("bf.out", "w", stdout);
#endif
	ori :: solve(); tot = 0;
	copytree(1, 0);
	while(m--) {
		int a = in, b = in;
		copytree(a, b);
	} 
	while(Q--) { ll x = lin, y = lin; printf("%lld\n", dist(x, y)); }
	return 0;
}
